As computing technology has advanced and the Internet has grown to allow many different devices to communicate with one another, the transfer of content among devices has grown dramatically. Many different types of content can be transferred, but the transfer of audio and audio/video content, such as songs and movies or television programs, has become increasingly commonplace. In many situations, content is encrypted in order to allow the content owner (e.g., the owner of the copyright in the content) to control how the content is used. Such encryption, however, can create obstacles to using the content for authorized users of the content, such as those that have purchased a license to use the content.
One recent trend is for content owners to distribute their content in unencrypted form. This allows the obstacles placed in the way of legitimate users of encrypted content to be avoided. However, this also leaves the copyright owner open to the possibility of the content being used by unauthorized users. This can be problematic for the content owner because in many cases the content owner's primary business model is charging each unique user for access to the content.